Which brings up a separate but related issue. I've never done a 4-hour training run and I doubt I ever will. In fact, I think I've only ever done one 3-hour training run and that was by mistake when I had my wife drop me off on a section of the Cape Cod rail trail and pick me up somewhere way down stream--and it wound up being a lot hotter and there was much less water on the trail than I expected. There is definitely a point of diminishing returns in long runs. I'm sure, again, there are individual differences but I have a hard time believing that most people are getting much out of a run longer than about 2.5 hours. I think by that time most people have just about exhausted every system and muscle fiber in their bodies, have gotten about all the training stimulus they are going to out of the run and are just bludgeoning themselves needlessly, resulting in a prolonged recovery or worse.

And, I don't think there is much to be gained runnning over 3 hours, either. Even when I ran for the Marine distance team, we never went over 3 hours. I absolutely agree with the point about diminishing returns. The only exception might be for someone running their first marathon. However, that has little to do with the training benefit, and more to do with instilling the confidence that you know you can stay upright on your feet that long....

So what's everyone else think?
I've read most of the major marathon writers. Some recommend rarely if ever running more than 18 miles. A lot of them suggest that 20 milers ought to be the maximum. A few say 22-23. Galloway suggests running training runs as long 30 miles.
Some recommend long runs each week, with the distance cut every other week (as in 18 one week, 12 the next, 20 the next, etc). Others recommend long runs only every 2nd or 3rd week.
What is your experience with all of the above?
And to address Mikey and Pron8r's main point - I'm having one problem with it. Here's the thing: at long run training pace of 1-2 minutes slower than marathon pace (the expert seem to agree that long runs should be significantly slower than MP), I personally CAN'T get in even an 18-20 miler in less than 3 hours. My goal pace right now is a sub-4:00 marathon, which puts me at a little over 9:00 race pace.
Which means on a long training run, even if I'm pushing it, I don't think I should be doing much faster than 10:00 miles. (Or should I be?) If I'm right ... then 18 miles takes me 3 hours. 20 miles and I'm approaching 3:30.
See my problem?
An aside here: I actually think Mikey is right - I think it's probably better for your body to cap it at 2:30 or so. I'm jealous of elite marathoners, because in my way of thinking, it's EASIER for them to run a marathon. Sure they work harder ... but they're done in 2:30. My last marathon was miserable - I had, um, some serious problems that I won't bore with - but I ran the first half in about 1:55 ... and the second half in THREE full hours. Being out there almost 5 hours was a horrible experience. I don't know how 6 hour marathoners do it.
Back to my questions for Mikey and Pron8r and whoever: I completely understand about diminishing returns and that moment when it goes from training to hurting. I experienced it the other day. At 3:10, I felt great. Could have run 50 miles. At 3:15, I suddenly felt like I was being beaten with baseball bats.
I assume that was the point where I depleted my glycogen stores (and I wasn't replacing calories and nutrients well enough ... I'd only brought one Gu with me).
So is *that* why the long runs have diminishing returns - is it the glycogen thing? Is it going past that that might be a bad idea?
And is glycogen depletion based on mileage ... or on time on your feet? If it's time spent running ... do you sub-3:00 runners never hit a wall?
For the record, I'm likely never going to be capable of running much better than a 3:30 marathon (8:00 pace), which means my long training runs will never be much faster than 9:00-10:00. So any 20-mile training run is always going to be a minimum of 3 hours.
For what it's worth, part of the reason I think you might be onto something - for me, at least - is the fact that for my last marathon, I had several 20+ mile runs and one 24 miler ... and the race was miserable. Meanwhile, I ran my current PR after seriously undertraining, and did it with one 10-mile run and one 13-mile run as my longest training efforts.
So maybe I need to look at rethinking the 18+ runs.
Or maybe it'll take a few more years to figure out what works best.
And maybe it's all highly individual.
Insert your thoughts here:

Jake, thanks for asking these questions--even though it will be a long time before I contemplate training for a marathon I've still been wondering how the overall time span of a long run should differ for a slower runner (like me).

'16 Goals:

• Do some dus...and some CX...and some tandem gravel...and some podiums...

• PRs

• 130#s (or less)

• Stop letting my core go to hell

Mile Collector

Abs of Flabs

posted: 10/5/2006 at 11:57 AM

Umm... there are so many questions that I can't remember them all, never mind answering. I'll just type whatever that comes to mind...
rain drops on roses
I suppose I should put on the standard disclaimer that everyone's different and YMMV... I agree with Pron8r that if you're training for the marathon for the first time, you should run more than 20 miles just so you would know what it feels like and to know that you can do it. I also believe that even if you've done a handful of marathons, you still should do at least a 20+ miler to simulate the marathon as closely as possible.
whiskers on kittens
Running 18 miles for your longest run is not the same as going all the way. It's nice to complete your long runs in under 3.5 hours, but you have to remember that during the actual race, you will be out much longer if you're a slower runner. Unpredictable things happen to your body and your mind when you go beyond 20 miles. If you complete that distance during training, you'll have the confidence knowing you can do it, as well as being physically prepared for what to expect during those few last miles. You don't want to be caught by surprise after 22 miles.
bright copper kettles
I think the 3 hour rule tries to reduce your recovery time. If you run much longer than that, you'll take much longer to recover because you exhausted your glycogen stores, which will make you miserable the following week, or you'll end up not running at all. If your stomach can handle it, you can reduce your recovery time by eating on the run. Take a gel regularly, or eat a granola bar, or some other source of carbs. Eat immediately after you're done will also help.
warm woolen mittens
As Pron8r so eloquently pointed out in another thread, if you want to run fast, then you should run fast during your training. You get what you train for. I'll unplug my mind now.

I think the 3 hour rule tries to reduce your recovery time. If you run much longer than that, you'll take much longer to recover because you exhausted your glycogen stores, which will make you miserable the following week, or you'll end up not running at all. If your stomach can handle it, you can reduce your recovery time by eating on the run. Take a gel regularly, or eat a granola bar, or some other source of carbs. Eat immediately after you're done will also help.
As Pron8r so eloquently pointed out in another thread, if you want to run fast, then you should run fast during your training. You get what you train for. I'll unplug my mind now.

'16 Goals:

So many questions, so little time. I'm leaving right after work for St. George for this weekend's marathon. When I return, I'll share the difference in my training from running only 3 marathons (last year) to running seven (one per month) this year. In the meantime, a couple of brief comments (no, they have nothing to do with underwear):
My experience (mind you, I have only run about 20 marathons total) is that the "wall" is distance-related, not time. And, with most runners, it is right around the 18-20 mile mark. In point of fact, if a marathon was only 20 miles, a lot more runners would run it--and fairly fast. The "wall', btw, has little to do with the fact that you hurt in the latter stages of a marathon. All runners feel the last few miles--even the elites. The wall has everything to do with, primarily, glycogen depletion and/or poor training. Your fuel cells have run dry. At that point, you will feel light-headed, dizzy, disoriented, weak, or some combination thereof (see Paula Radcliffe and the last Summer Olympics). I have only hit the wall once in my marathons. And, I know exactly why. Is it inevitable that a runner will hit the wall? No. And, you don't need to (and shouldn't) hit it in training.
I'll expand on this when I return. Certainly anxious to hear what others have to say.

Alright, I'll give this a shot.
A) I agree with not going beyond about 20 miles for marathon training, especially for someone who is new to it, but even for experienced runners. The reason is that you increasing risk of injury the longer you go.
B) My experience is building up mileage steadily over several weeks (up to 20 mi), then doing a 20, next week a 12, then 20, then 12, then 20, then 12, into the taper for three weeks.
C) If you're a slower runner (not being rude, just can't think of better words), I think it's even MORE important to run the long distances, and NOT go by time for those. The reason being is that your body needs to know what it feels like, but even more so mentally.
D)As for the glycogen thing, it's based on exertion. The more effort you exert, the faster you burn the glycogen. Now, we will all burn use up our glycogen stores, regardless of who you are, in the course of the marathon, so your body now has to find alternate sources of glycogen. In endurance events, your body wants to burn fat if it can, but it will burn muscle as well. So, long runs train our bodies to burn more fat. However, again, if you're over-exerting yourself, you strain your body to the point where it can no longer burn fat efficiently, and that's where people tend to "bonk".
If it helps, I have a link for a marathon training plan that doesn't go over about 18 or 19 miles. But you run 'em fast.
http://www.runningtimes.com/rt/articles/?id=4835&page=6&c=83#program

Several have already made what I believe to be the most important point. Run long enough to learn how YOUR body reacts to time/distance! Run long more than once to also learn what kinds of things you can do to help your body get through the trauma of running long. Whatever your goal race distance is, I firmly believe that race day is NO time to experince that distance for the first time!
For those of us that are slower runners, we are going to be out there longer than the elites. One really cool thing about that is that the longer we are out there, the more justification we have to REPLACE lost fuel! OK, OK, I know that probably isn't going to happen in a 10K, but I found that when I started eating something during the course of the marathon, I was able to push the wall further and further out. Yes, it still hurt...but I found my body dealing with it better and better. Interestingly enough, I have never run a marathon without hitting the wall, but I have run several longer distance races with no sign of it.
As for recovery versus time on your feet...I can do a whole 'nuther sermon on picking the right surface...the roads are WAY harder on recovery than the trails.
Anyway, really interesting post. I love hearing all the different experiences. Again, I think someone else captured this but, everyone is different and what works for me may not work for you...
Good luck, getting my stuff ready for my long run tomorrow night (full moon in NTex acquired at 10:13 pm).
Have a great weekend!
Lynn B

""...the truth that someday, you will go for your last run. But not today—today you got to run." - Matt Crownover (after Western States)

Okay so this thread grew up fast!
I agree that first time marathoners should do one or two runs of 20 or so miles regardless of how long it takes--building in proper recovery time after--to prepare themselves mentally and psychologically for the full 26.2. I should have included that disclaimer in the paragraph Jake quoted. But I don't think most experienced marathoners, regardless of speed ever need to run 3 hours in training so long as they are doing the weekly mileage with a mid-week medium-long run. I just don't think the return on investment is there. A 30K or 20M race as part of a buildup, now that's a different story for a lot of reasons. Way more bang for your buck there. Long runs are important but are easily the most over-emphasized aspect of marathon training.
Regarding pace I agree that long runs should average slower than MP but I never average close to 1 or 2 minutes slower for the whole thing and some sections are definitely at or below MP. My typical long run for a marathon winds up more like 30 seconds per mile slower than MP if not less. Also, the slower the runner the closer his/her MP will be to his/her every day easy pace. So for a 4.5 hour marathoner, his or her MP might actually be the same as easy pace and therefore long runs will be at that pace too. Make sense? I'm not sure what's the longest I could possibly run continuously but I'm pretty sure if I was going to attempt to run for 5 hours, I'd have to take it at a pace that's at least as slow as my easy pace.
Long runs at some point have diminishing returns because of glycogen depletion, yes, but also muscle exhaustion, cumulative damage done by the pounding and probably a few other factors. As Scout7 pointed out, glycogen depletion is a factor of time AND pace. Depletion happens much faster at higher effort levels because you can convert a lot less fat to fuel at faster paces. This is why intelligent pacing can be the difference between success and a spectacular crash and burn at the marathon.
Basically I agree 100% with Mile Collector that, late in a long run, it helps to think of a few of your favorite things.

My experience (mind you, I have only run about 20 marathons total) is that the "wall" is distance-related, not time. And, with most runners, it is right around the 18-20 mile mark. In point of fact, if a marathon was only 20 miles, a lot more runners would run it--and fairly fast. The "wall', btw, has little to do with the fact that you hurt in the latter stages of a marathon. All runners feel the last few miles--even the elites. The wall has everything to do with, primarily, glycogen depletion and/or poor training. Your fuel cells have run dry. At that point, you will feel light-headed, dizzy, disoriented, weak, or some combination thereof (see Paula Radcliffe and the last Summer Olympics). I have only hit the wall once in my marathons. And, I know exactly why. Is it inevitable that a runner will hit the wall? No. And, you don't need to (and shouldn't) hit it in training.

As for the glycogen thing, it's based on exertion. The more effort you exert, the faster you burn the glycogen. Now, we will all burn use up our glycogen stores, regardless of who you are, in the course of the marathon, so your body now has to find alternate sources of glycogen. In endurance events, your body wants to burn fat if it can, but it will burn muscle as well. So, long runs train our bodies to burn more fat. However, again, if you're over-exerting yourself, you strain your body to the point where it can no longer burn fat efficiently, and that's where people tend to "bonk".

Okay, here is the deal with glycogen. And no, I did not sleep in a Holiday Inn Express last night. Your body contains about 2000 kcal of energy stored as glycogen. and another 4000 kcal for EVERY pound of fat you have (e.g., a 150 lb person with just a 5% body fat will still have almost 8 lbs of fat, worth about 32 000 kcal!). Energy expenditure while running is a function of your weight, and to a lesser extent the grade of the road, and to a far far lesser extent to your pace. So an 8 m/m runner is burning energy at about the same rate PER MILE as a 12 m/m runner with the same weight while they are both running. A 150 lb runner will burn approximately 120 kcal per mile run.
Your body uses two fuel sources to run. One is glycogen. Glycogen is the primary energy source used for fight or flight type activites, which means it is the primary energy source used when running. When you run above 80-90% of your maximum effort (or VO2max, or Maximum HR), your body is burning almost entirely glycogen to fuel the effort. Below that, your body starts using the other energy source, which is fat. An innacurate but useful rule of thumb is that your body fuels its effort using glycogen as a percentage of total calories used that is equivalent to your perent effort. So if you are running at a 70% effort, about 70% of the kcal you are using to fuel the effort are coming from glycogen, and the rest come from fat.
The reason you bonk is that you run out of glycogen. If you weigh 150 lbs and are running 80% effort, you will use about 2000 kcal worth of glycogen in about 21 miles. If you are running at a 70% effort, it will take you 24 miles to use 2000 kcal worth of glycogen. So why do you bonk at mile 18? Well, even if you carb load absolutely perfectly (and most of us do not), when you finish loading, you then go to bed and sleep. When you wake up marathon morning, your body has used up as much as 25-30% of your glycogen just keeping you alive overnight. And the next morning, the little bit you are able to force down into your stomach, well it does not ever get a chance to be stored as glycogen.
Calories on the course? Sure, there are two general options. There are sports drinks, which deliver 4-10 kcal per cup, depending on how dilute the mix and how full the cup. And there are gu or jelly bean packets, which deliver about 100 kcal per packet, provided you can get every last bit. It takes about 1 1/2 packets of gu or about 15 cups of sports drink to fuel each additional mile (i.e., spare your body's need to burn glycogen)
When you bonk, you slow down. When you slow down, your body preferentially burns fat. That is how you can finish, even after bonking.
So, putting it all together, assuming that you weigh 150 lbs (thereby burning 120 kcal per mile), that you are running your marathon at 75% effort, and that you are able to store 2000 kcal, but that you also slept during the night and burned 25% of those calories, but that you take enough gu and sports drink to get 2 extra miles:
((2 000 * (1 - 0.25)) / (120 * .75)) + 2 = 18.6
You will bonk at mile 18.6. Or so. It is never quite this predictable.

However, eating about 400 kcal of mostly carbs about 3 hours before race time will replenish what you lost overnight (from your liver) and let you start with 2000. With proper pacing you might be able to generate another 500 kcals from metabolizing fat. Leaving our 150 lb. runner still 644 kcals short of what he/she needs to finish without bonking--so that's how much he or she would need to take in on the run and in the starting coral just before the gun. Weight makes a huge difference. A 200 lb runner will have a much greater deficit so will need to take in many more calories on course.

eating about 400 kcal of mostly carbs about 3 hours before race time will replenish what you lost overnight (from your liver) and let you start with 2000. With proper pacing you might be able to generate another 500 kcals from metabolizing fat.

Yes, but in the 3 hours after eating, provided maximal and immediate absorbtion, the runner will still be burning calories just to keep breathing and thinking. And the calories from metabolizing fat goes on regardless, and was included in the math above

I am ready for my 6th marathon next weekend (10/14) and in the training for the previous ones we have done two 20 milers, two 18 milers and two 16 milers as our longest runs with step back weeks in between. I think after your first marathon, you get a feeling, based on how that race went, for how you will need to train for your next one and you just adjust your schedule accordingly. I have a friend who insists on doing 22 and 24 miles for her training and it seems to be okay for her…of course I think she’s crazy.

"It is very hard in the beginning to understand
that the whole idea is not to beat the other runner.
Eventually you learn that the competition is against
the little voice inside you that wants to quit."
George Sheehan

Great stuff. Fascinating thread. Whoever start it should be given free beer for at least a month.
Really interesting about how pace affects glycogen depletion versus fat burning; I guess this is why a medium-slow pace on the treadmill lights up the little "fat burning" light?
I guess that also explains why, among the running experts that recommend the longer long runs (well over 20 miles), they insist that you keep it really slow - to keep it underneath that glycogen depletion pace?
So the next question is - as you train, are you actually improving your glycogen storage ability? In other words, assuming I don't actually run FASTER ... will the point at which I hit the 'wall' come later in a marathon? Can it eventually be pushed beyond 26 miles - if you maintain the right pace?
Do ultra runners avoid all this by staying at that 70% or less pace?
I guess in the end its going to take several years of experimenting to figure out what works for me. Thanks to all for all the info.